A standard connector or contact block in the electronics industry consists of a plastic holder having a plurality of small diameter, aligned, equally spaced holes within a face of the holder within which project male contact parts of a series of identical female contacts, whose female parts take the form of a rectangular box, in cross-section. Thus, each sheet metal contact or connector has a female part which is box shaped and a male part integral therewith and extending outwardly of the box and projecting through the opposite side of the plastic holder by penetrating completely a hole within the plastic holder. Plastic holders having holes spaced by 0.100 inches for receiving the male contact parts are standard in the industry. Additionally, the size of the contacts which fit into the holes is standard and thus the dimensions of the female contact box are also standard in the industry.
Typically, such contacts are stamped out as a plurality of identical units simultaneously from sheet metal stock. When stamped out, the box material portions or blanks of the contacts are initially flat with a male contact part integral with the box material portions and extending axially from the center thereof to facilitate the multiple steps in the completion of the connectors or contacts. A carrier strip portion of the sheet metal stock remains connected to all of the "flattened" box material portions of the contacts via small thin leads aligned with the male contact parts.
In the past, the contacts after flat sheet stamping were folded to form the female contact boxes, and after separation from the carrier strip, individually, the male parts were placed in one of the holes in the plastic holder.
Due to the necessary "standard" size of the boxes for the contacts, the width of the "flattened" box is of a given dimension, i.e., dimension D, for instance, of 0.207 inches. The center-to-center spacing of the contacts at the time they are initially stamped out and commonly connected to the carrier strip is 0.230 inches. This dimension is mandated by the width of the "flattened" box material. It is neither equal to nor a multiple of the "spacing" between the holes within the plastic holders. Thus, the typical stamping process parameters frustrate attempts to effect simultaneous insertion of the male contact parts within respective aligned holes within the plastic holders ultimately receiving the same prior to separation from the common carrier strip support.
The female electrical contacts conventionally known as dual beam female electrical contacts mate with contacts on circuit boards and receive male pin connectors. Typically, the female electrical contacts include a female contact portion of rectangular box cross-section including laterally opposed finger projections or beams which have bent, oblique portions creating an entranceway for the male contact pins to effect the electrical connection between a male contact pin and the female box contact. The lateral beams are integrated to the female contact center line or spine. In the known processes for stamping dual beam contacts, it is important to minimize wastage of the flat metal strip stock subject to the stamping process since such waste materially increases the cost of manufacture of the dual beam contacts.
U.S. Pat. No. 4,480,386, issued to John E. Adams on Nov. 6, 1984 and entitled Process for Producing Dual Beam Electrical Contact, shows a typical sequence of stamping out and forming a plurality of dual beam female box-type contacts with the contacts each being joined to a carrier strip by means of small leads as an extension of the spine. As may be seen from the patent, the flat metal strip stock is first punched to form a series of circular, longitudinally spaced pilot holes which holes are used to guide the strip stock for further stamping. The flat metal stock material is moved sequentially in the direction of the path defined by the pilot holes and subjected to a series of reciprocating punches. Typically, a first punch prescribes the outlines of the beams, the center line or spine, and any tabs. The punches at succeeding stations may function to separate adjacent contacts by effecting a slitting action separating the contacts by a thin transverse line and completely separate the beams with the exception of a juncture at one end to the female contact box material portion. The punch operations may be simplified by using a single punch for effecting the complete outline and a second punch to effect the slitting operation separating the contacts laterally. Further, portions of the sheet stock as, for instance, the end of the beams, may be swaged during a given one of the punch steps.
Once the components are "stamped out", it is conventional to plate all or some of the contact surface area with a highly electrical conductive metal coating prior to folding the flattened box portion and additional portions thereof to complete the essentially closed, rectangular, female contact box. Such actions constitute either a single forming step or a sequence of forming steps during which the beams are bent upwardly at right angles to the center line or spine, and the outer edges of the flattened box sheet stock material are in turn bent at right angles to the beams into coplanar, edge end facing position. In view of the standard dimensional requirements for the female contact box, the lateral width of the flattened box is invariable in terms of the final product.
It is, therefore, a primary object of the present invention to produce a female, dual beam box contact of standard box dimensions with minimal center-to-center spacing permitting group mounting of a plurality of such contacts while linked to the carrier strip for insertion within respective holes of a plastic holder and wherein the center-to-center spacing of the contacts is equal to or a multiple of the center-to-center spacing of the holes within the plastic holder receiving the same, without compromising the necessity of the width of box material of the contacts, when flattened, to be in excess of the center-to-center spacing of the contacts on the carrier strip.